§2023-03-31

1. Install

$ sudo pacman -S docker
resolving dependencies...
looking for conflicting packages...

Packages (4) bridge-utils-1.7.1-1  containerd-1.6.19-1  runc-1.1.4-1  docker-1:23.0.1-1

Total Download Size:    39.23 MiB

2. start docker.service

[alexlai@hc4MnGnome ~]$ systemctl status docker
○ docker.service - Docker Application Container Engine
     Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; preset: disabled)
    Drop-In: /etc/systemd/system/docker.service.d
             └─override.conf
     Active: inactive (dead)
TriggeredBy: ○ docker.socket
       Docs: https://docs.docker.com
       
$ sudo systemctl start  docker

3. add alexlai to docker group

$ sudo usermod -a -G docker alexlai

4. /usr/lib/systemd/system/docker.service

[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target docker.socket firewalld.service containerd.service time-set.target
Wants=network-online.target containerd.service
Requires=docker.socket

[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutStartSec=0
RestartSec=2
Restart=always

# Note that StartLimit* options were moved from "Service" to "Unit" in systemd 229.
# Both the old, and new location are accepted by systemd 229 and up, so using the old location
# to make them work for either version of systemd.
StartLimitBurst=3

# Note that StartLimitInterval was renamed to StartLimitIntervalSec in systemd 230.
# Both the old, and new name are accepted by systemd 230 and up, so using the old name to make
# this option work for either version of systemd.
StartLimitInterval=60s

# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity

# Comment TasksMax if your systemd version does not support it.
# Only systemd 226 and above support this option.
TasksMax=infinity

# set delegate yes so that systemd does not reset the cgroups of docker containers
Delegate=yes

# kill only the docker process, not all processes in the cgroup
KillMode=process
OOMScoreAdjust=-500

[Install]
WantedBy=multi-user.target

5. HOW TO MOVE DOCKER DATA DIRECTORY TO ANOTHER LOCATION ON UBUNTU

• defaul data directory is

$ sudo ls -l /var/lib/docker/
[sudo] password for alexlai: 
total 44
drwx--x--x 4 root root 4096 Mar 31 10:16 buildkit
drwx--x--- 2 root root 4096 Mar 31 10:16 containers
-rw------- 1 root root   36 Mar 31 10:16 engine-id
drwx------ 3 root root 4096 Mar 31 10:16 image
drwxr-x--- 3 root root 4096 Mar 31 10:16 network
drwx--x--- 3 root root 4096 Mar 31 10:16 overlay2
drwx------ 4 root root 4096 Mar 31 10:16 plugins
drwx------ 2 root root 4096 Mar 31 10:16 runtimes
drwx------ 2 root root 4096 Mar 31 10:16 swarm
drwx------ 2 root root 4096 Mar 31 10:16 tmp
drwx-----x 2 root root 4096 Mar 31 10:16 volumes